How much labor did it take to construct a Viking longship?

This is another in my series of posts on ancient finances.
Let’s ponder how much time it would take to construct a Viking longship and consider how much of an investment that would be for a community. Any way you look at this, a longship is a major capital asset.
(Cross post from Attestation Update.)
One estimate of time to build a longship
Philip Line, in his book The Vikings and Their Enemies – Warfare in Northern Europe, 750 -1100 written in 2014, provides one framework for the investment in a longship.
I’ll quote and then expand his comment on page 51:
“Experimental archaeologists have estimated that 40,000 working hours may have been needed to produce all the components of a 30-meter longship, consuming the surplus production of 100 persons for a year.”
Surplus production in the Viking context would be the amount of time not needed for subsistence living. In other words the amount of effort a warrior would have after raising enough food to feed his family with enough left over to survive the next winter.
If 40,000 hours is enough time for 100 warriors, that would be 400 hours each. Let’s assume that would be spread over a year except for my assumption that during the worst three months of winter no construction could be done. Since we are talking rough numbers let’s spread that 400 hours over nine months, which would be 44 hours a month, which would be about 11 hours a week.
So 100 warriors working 11 hours a week for 9 months would be needed to construct a longship.